The Design And Research Of Motor Control System For Accurate Sprayer

It is a common agricultural activity to perish the plant diseases and insect pests in the agricultural product. Spraying is one of the important parts of the agriculture, and has important function: insufflate the weedicide to perish the weed, insufflate the pesticide to prevent and cure the plant diseases and insect pests and so on. But if we make use of the existing machine and technology, the efficiency of using is not more than 30%, while the losing amount of pesticide is more than 70% and the rate of asymmetry of distributing of pesticide is more than 46.6%. So it causes the large economic loss and the sever environment pollution. All are due to our behindhand mechanism of protecting plant and technology of spraying pesticide. So it is necessary to develop a kind of high efficiency, economic and safety sprayer.The paper is based on the need of accurate and automatic spraying, and it makes the technology of controlling the single chip and adjusting the speed of direct current motor become its core. It designs a multi-muzzle auto spray system, and applies fuzzy control technology to the timing of direct current motor to do emulate study.The part of timing is a double closed loop DC timing system, and it is composed of rev loop (internal loop) and current loop (external), which are series-wound. The output of rev loop is the input of current loop. It applies Pulse Width Modulation control technology, which makes use of the time proportion of turn-on and disconnect of power switch to the control of the voltage of DC motor, thereby it can control the rotate speed of muzzle rotor. We adopt traditional PID arithmetic to control current loop, and we adopt fuzzy control arithmetic to control rev loop, for rev loop is affected by many kinds of linear factors.The paper designs a fuzzy-controller based on the experts' knowledge and practice experience. It contains the choice of input-output variable domain, fuzzy subset and conformation of membership function of each subset; the design of fuzzy control rules and fuzzy reasoning system and so on. Then it makes use of SIMULINK to do emulate study to the fuzzy model that has been designed. The result of emulates shows that it accords with the needs of spraying accurately in agriculture.For the software system, we adopt assemble language to deal with datum and control program, so as to realize the on-line and real time control.In a word, the paper expatiates the design of the new-style multi-muzzle sprayer in detail, and do experiments on mechanism and circuit. The emulate results show it correct.